THE BIRDS OF SOUTH-WEST AND PENINSULAR SIAM. 49 



October, which vvc believe to be this form, but pending the receipt of 

 adult birds in breeding plumage the identitication is doul)tful. Im- 

 mature and wintei" plumage specimens of H. hyhrUhi, appear to have 

 the crown more streaked than in this species. 



48. Hydroprogne caspia (Pall.). ^ 



Sterna caspia, Pall., Nov. Oouiiu. Petrop. xiv, i, p. 582, tub. xxii, 



fig. 2 (1770). 

 Hydroprofjne caspia, Williamson, Jouiii. Nat. Hi.st. 8oc. Siam, iii, 



1918, p. 37 (Tachin, Inner Gulf of Siam). 



The birds obtained by Williamson at Tachin are the only re- 

 cords for this species from Siam. The bird is the largest of all the 

 terns, with a wing exceeding 400 mm. (16 inches), and with an excep- 

 tionally heavy bill. 



49. Gelochelidon ang-lica (Mont.). 



Sterna ancjlica, Mont., Orn. Diet. Suppl. 1813, fig. (Su.s.sex) ; 



Williamson, Joarn. Nat. Hi.st. See. Siam, ii, 191G, p. 62 (Inner 



Gulf of Siam). 

 Gdoclielidon auylica, A., p. 491 (Mergui) ; H. Saunders, Cat. Birds 



Brit. Mus. XXV, 1896, p, 31., spm. s' (Pakchan). 



Very common in the Straits of Malacca in the winter months : 

 we have not ourselves met with it in Siamese waters. 



50. Seena seena (Sykes). 



Sterna seena,Syke><, v. Z. S. 183l.^ p. 171 (Deccau) ; I., p. 148 

 (Koh Lak). 



Gyldenstolpe's record of this river tern from Koh Lak is the 



most southerly one. The .species is not found in the Straits of 



Malacca, and Kelham's records (Ibis, 1882, p. 201) are referable to 



Sterna media Horsf. We have examined his specimens, which are 



preserved in the Raffles Museum, Singapore. 



51. Sterna bergii pelecanoides (King). 



Sterna cristata. Staph, in Shaw's Gen. Zool. xiii, Pt. 1, 1825, p. 

 146 (China). 



Sterna pelecanoides. King, Surv. Inter trop. and West Coast Austra- 

 lia, Vol. 2, 1827, p. 422 (Tones Straits). 



Sterna hercjii, A., p. 493 (Bokpyin) ; C. ii, p. 428; E., p. 11 

 (Terutau) ; Williamson, J.iurn. Nat. Hi^t. Sec. Siam. iii, 1918, 

 p. 83 (Koh Rin and Koh Cbuan, Inner Gulf of Siam). 



!• Gyldenstolpo, Kungl. Sv. Vet. Akad. Himdl. M. Baker, .Jouin. X. H. Soc. Siam, iii, 1919. 



56, No. 2, 1916. (Hist part). 



J. Robinson, .lourn. K. M. S. Mus. vii, 1917. Baker, Joinn. X.H. Soc. Siam, iii, 1919. 



K. Kloss, Il>is, 1918. (second part). 



U. Koliinson and Kloss, .Tourn. X. n. Soc. R^am, M.I. Baker, Journ. X.H. Soc. Siam, iv, 19'.J0. 



iii, 1919. (third part). 



VOL. V, NO. 1, 1921. 



